One of the major problems child specialists face daily is the school-age hyperactive child. Research on hyperactivity suffers from many glaring methodological errors. Drug effects are usually evaluated by professinal opinion or rating scales, but not with naturalistic measures of behavior. Well-controlled studies in laboratory environments are not applicable to the natural environment. Clearly, a technology to measure hyperactive behavior in its natural environment is needed. The goal of the two year research project isto develop two objective measuress of hyperactivity: (a) motor behavior and (b) social behavior. A video tape technology will be developed to measure hyperactivity in the classroom. The project will be aimed primarily at the training of a staff to analyze motion and social interaction from the video tapes, the development of equipment systems to rapidly and efficiently code data from the video tapes, and to obtain a general and systematic analysis of what constitutes hyperactivity in the child's natural environment. The results of this research will be (a) the development of a naturalistic measurement technology for studying hyperactive children and (b) a definitive analysis of hyperactive behavior within and across home and school settings. These procedures and research findings will be of great value to investigators who wish to assess the effects of various treatment straegis for hyperactivity.